<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>引出生命周期</title>
    <script type="text/javascript" src="../js/vue.js"></script>
</head>
<body>
    
    <div id ="root">
        <h2 v-if="a">你好啊</h2>
        <h2 :style="{opacity}">欢迎学习vue</h2>
    </div>
</body>
 
   <script type="text/javascript">
    Vue.config.productionTip = false //阻止 vue 在启动时生成生产提示。

    new Vue({
        el:'#root',
        data:{
            a:false,
            opacity:1
        },
        methods:{

        },
        //Vue完成模板的解析并把初始的真实DOM元素放入页面后（挂载完毕）调用mounted
        mounted(){
            console.log('mounted',this)
            setInterval(() => {
                this.opacity -= 0.01
                if(this.opacity <= 0) this.opacity = 1
            },16)
        },
    })
   </script>

</html>